Ordinarily, in cases where electrodes are formed on insulating substrates or electronic elements, etc., a known method is that an organo-metallic paste is first prepared by mixing and kneading a powdered metal or organo-metal complex with a resin or organic solvent, etc.; this organo-metallic paste is applied to the surface of the insulating substrate or electronic element by a method such as screen printing, etc., so that a specified circuit pattern is formed; and then this pattern area is heated so that the organic component is broken down and evaporated, thus depositing the metal in the form of a film. Furthermore, in cases where ornamental metallic films are formed on the surfaces of ceramics, etc., since a metal liquid which has little viscosity is required, an organo-metal complex which is soluble in organic solvents is selected, and an organo-metal liquid is prepared by dissolving or dispersing this complex in such an organic solvent. As seen from the above, organo-metal complexes are currently used in a broad range of fields such as electronic instruments, ceramics and industrial arts, etc.
Conventionally, balsam type compounds, e.g., terpineolgold sulfide (C.sub.10 H.sub.18 SAuCl.sub.x), terpineolplatinum sulfide (C.sub.10 H.sub.18 SPtCl.sub.x) and terpineolpalladium sulfide (C.sub.10 H.sub.18 SPdCl.sub.x), etc. have been known as organo-metal complexes used in such applications. These compounds are also referred to in abbreviated form as gold balsam, platinum balsam and palladium balsam. In addition, other noble metal balsams such as rhodium balsam and ruthenium balsam, etc. are also known.
When such conventional balsam type compounds are used as raw materials for metal compositions such as metal pastes and metal liquids, etc., the problems described below are still encountered.
First of all, in cases where metals are to be deposited using such metal compositions, a firing process cannot be avoided in the manufacturing process. Since balsam type compounds contain chlorine and sulfur, SO.sub.x and Cl.sub.2 are inevitably produced as by-products in the firing process; and when these harmful substances are released into the atmosphere, this not only causes a deterioration in the health environment of the workers, but also has a deleterious effect on the natural environment in general. Furthermore, extensive equipment such as desulfurizing equipment, etc. is required in order to recover these harmful substances, and 100% recovery of the substances is difficult. SO.sub.x and halogens may also damage the equipment used for firing, so that there is a need for safer metal compositions for forming metallic films.
Secondly, the SO.sub.x and halogens generated during firing may in some cases have a deleterious effect on the base material being fired. When the base material is heated, components other than metals are broken down and evaporated; however, SO.sub.x and halogens may corrode the base material, and in some case, sulfur atoms and halogen atoms may be diffused as impurities inside the base material. Especially in cases where the base material constitutes an electronic element, there have been instances in which such diffusion has a deleterious effect on the electronic characteristics of this electronic element.
Third, there are limits to the organic solvents that can be used in cases where organo-metal liquids are manufactured from balsam type compounds. For example, such compounds show a high solubility in aromatic solvents, but are almost insoluble in alcohol type solvents. Furthermore, the same limitations also apply to the resins that are required in order to manufacture an organo-metal paste. For example, in cases where the resin used is a nitrocellulose resin, this resin is soluble in solvents such as butylcarbitol and butylcarbitol acetate, etc. but is insoluble in terpineol. Accordingly, if the solvents are limited on the organo-metal complex side, the resins that can be used are also naturally limited; consequently, the types of metal pastes that can be manufactured are limited, and the applications of these pastes are also limited.